All of the following cause soil degradation except? (a) adding chemicals
(b) deforestation
(c)overgrazing to soil
(d) contour ploughing

Use the normal approximation to the binomial distribution to answer this question. fifteen percent of all students at a large university are absent on mondays. if a random sample of 12 names is called on a monday, what is the probability that four students are absent?

What are the constants in this expression? -10.6+9/10+2/5m-2.4n+3m

How do you use the elimination method for this question? explain, because i really want to understand!